Biology subjects

Bonnot, T.

Publications and source records attributed to Bonnot, T..

2 recordsLinked to original sources

bioRxiv2024

Molecular signatures and associated regulators of the pea leaf response to sulfur deficiency and water deficit as revealed by multi-omics analyses

Sulfur availability affects crop yield, seed quality, and tolerance to environmental constraints. To understand how pea (Pisum sativum) leaves respond to sulfur deficiency alone or combined with moderate water deficit during the early reproductive phase, we employed a multi-omics approach. Sulfur deficiency reduced plant height, biomass and leaf carbon, and increased the nitrogen-to-sulfur ratio. Under this condition, 38 genes were up-regulated at both transcript and protein levels, including genes involved in sulfur metabolism and antioxidant responses, suggesting coordinated molecular adjustments that may mitigate low leaf sulfur status. Moderate water deficit alone had limited effects, but markedly altered plant growth, gene regulation and metal accumulation when combined with sulfur deficiency. Among synergistically up-regulated genes, twenty were linked to reactive oxygen species responses and activated early, while seven genes with sustained activation encoded glutathione S-transferases. This was associated with higher GST activity and likely contributed to limiting H2O2 accumulation in double-stressed leaves. One-third of differentially accumulated proteins were encoded by genes showing no transcriptional change under stress, including temperature-induced lipocalins with potential protective roles under combined stress. These findings enhance our understanding of multilevel molecular responses to stress interactions, which is essential for improving crop resilience under multi-stress conditions. HighlightModerate water deficit amplifies molecular responses to sulfur deficiency in Pisum sativum, revealing synergistic responses at multiple layers of regulation under this stress combination.

plant biology↗

bioRxiv2023

Time of day and genotype sensitivity adjust molecular responses to temperature stress in sorghum

Sorghum is one of the four major C4 crops that are considered to be tolerant to environmental extremes. Sorghum shows distinct growth responses to temperature stress depending on the sensitivity of the genetic background. About half of the transcripts in sorghum exhibit diurnal rhythmic expressions emphasizing significant coordination with the environment. However, an understanding of how molecular dynamics contribute to genotype-specific stress responses in the context of the time of day is not known. We examined whether temperature stress and the time of day impact the gene expression dynamics in cold-sensitive and tolerant and heat-sensitive and tolerant sorghum genotypes. We found that time of day is highly influencing the temperature stress responses, which can be explained by the rhythmic expression of most thermo-responsive genes. This effect is more pronounced in thermo-tolerant genotypes, suggesting a stronger regulation of gene expression by the time of day and/or by the circadian clock. Genotypic differences were mostly observed on average gene expression levels, but we identified groups of genes regulated by temperature stress in a time-of-day and genotype-specific manner. These include transcriptional regulators and several members of the Ca2+-binding EF-hand protein family. We hypothesize that expression variation of these genes between genotypes may be responsible for contrasting sensitivities to temperature stress in tolerant vs susceptible sorghum varieties. These findings offer a new opportunity to selectively target specific genes in efforts to develop climate-resilient crops based on their time of day and genotype variation responses to temperature stress.

plant biology↗